SYNTHESIS OF ENAMINO KETONES FROM 4,5-DIHYDROPYRAZOLES
1811
2
14.97 (CH3CH2), 16.21 (3-Me), 17.18 (MeC=C), 26.10
(5-Me), 55.50 (C4), 58.42 (OCH2), 64.45 (C5), 85.52
(C=CH), 150.02 (C3), 155.99 (MeC=C), 168.65 (C=O).
Found, %: C 64.34; H 9.06; N 12.37. C12H20N2O2. Cal-
culated, %: C 64.26; H 8.99; N 12.49.
2.89 d (1H, 4-HB, J = 17.9 Hz), 5.50 s (1H, C=CH).
13C NMR spectrum, δC, ppm: 8.10 (5-CH2CH3), 10.64
(3-CH2CH3), 17.11 (5-Me), 23.52 (5-CH2), 25.27
(MeC=C), 31.26 (3-CH2), 31.96 (MeC=O), 50.13 (C4),
67.92 (C5), 100.31 (C=CH), 156.94 (C3), 157.42
(MeC=C), 195.02 (C=O). Found, %: C 70.46; H 9.82;
N 12.17. C13H22N2O. Calculated, %: C 70.23; H 9.97;
N 12.60.
Ethyl 3-(3,5-diethyl-5-methyl-4,5-dihydro-1H-
pyrazol-1-yl)but-2-enoate (IVh). Yield 97%, viscous
oily substance. IR spectrum, ν, cm–1: 455, 533, 567,
632, 733, 800, 898, 932, 992, 1057, 1110, 1130, 1175,
1272, 1318, 1343, 1392, 1428, 1468, 1583, 1642, 1667,
Ethyl 3-(4,5-dihydro-1H-pyrazol-1-yl)but-2-en-
oate (IVe). Yield 97%, viscous oily substance. IR spec-
trum, ν, cm–1: 483, 525, 648, 709, 833, 903, 925, 998,
1047, 1118, 1158, 1272, 1342, 1358, 1420, 1567, 1593,
1675, 2905, 2938, 2983, 3083. H NMR spectrum, δ,
ppm: 1.25 t (3H, CH2CH3, J = 7.2 Hz), 2.61 s (3H,
MeC=C), 2.93 t.d (2H, 4-H, J4, 5 = 10.1, J3, 4
1.1 Hz), 3.58 t (2H, 5-H, J4,5 = 10.1 Hz), 4.10 q (2H,
OCH2, J = 7.2 Hz), 4.58 s (1H, C=CH), 6.85 unre-
1
2892, 2950, 2987. H NMR spectrum, δ, ppm: 0.76 m
(3H, 5-CH2CH3), 1.07 m (3H, 3-CH2CH3), 1.18 m
(3H, OCH2CH3), 1.47 s (3H, 5-Me), 1.58 m (1H,
5-CHA), 2.11 m (1H, 5-CHB), 2.24 m (2H, 3-CH2),
1
3
2
3
3
2.54 s (3H, MeC=C), 2.60 d (1H, 4-HA, J = 17.7 Hz),
=
2
2
3
2.81 d (1H, 4-HB, J = 17.7 Hz), 4.02 q.d (OCH2, J =
3
13
3
1.7, J = 7.1 Hz), 4.92 s (C=CH). C NMR spectrum,
δC, ppm: 8.20 (5-CH2CH3), 10.72 (3-CH2CH3), 14.61
(OCH2CH3), 16.81 (5-Me), 23.46 (5-CH2), 25.27
(MeC=C), 30.98 (3-CH2), 50.03 (C4), 58.28 (OCH2),
67.68 (C5), 84.13 (C=CH), 155.40 (C3), 156.65
(MeC=C), 169.09 (C=O). Found, %: C 66.25; H 9.29;
N 11.02. C14H24N2O2. Calculated, %: C 66.63; H 9.59;
N 11.10.
13
solved triplet (1H, 3-H). C NMR spectrum, δC, ppm:
14.50 (CH2CH3), 15.36 (MeC=C), 33.47 (C4), 44.47
(C5), 58.51 (OCH2), 86.28 (C=CH), 144.26 (C3),
156.53 (MeC=C), 168.58 (C=O). Found, %: C 59.20;
H 7.54; N 15.96. C9H14N2O2. Calculated, %: C 59.32;
H 7.74; N 15.37.
Ethyl 3-(5-methyl-4,5-dihydro-1H-pyrazol-1-yl)-
but-2-enoate (IVf). Yield 98%, viscous oily substance.
IR spectrum, ν, cm–1: 483, 532, 642, 715, 775, 802,
842, 883, 933, 950, 1023, 1041, 1092, 1122, 1250,
1292, 1308, 1322, 1342, 1350, 1400, 1550, 1580, 1667,
5,5-Dimethyl-3-(5-methyl-4,5-dihydro-1H-pyra-
zol-1-yl)cyclohex-2-en-1-one (IVi). Yield 97%, vis-
cous oily substance. IR spectrum, ν, cm–1: 433, 457,
497, 665, 697, 717, 797, 817, 853, 883, 900, 933, 947,
987, 1007, 1060, 1073, 1097, 1140, 1163, 1180, 1233,
1260, 1353, 1413, 1540, 1626, 2833, 2940, 3053.
1H NMR spectrum, δ, ppm: 1.13 s (3H, 5′-Me), 1.18 s
1
2833, 2858, 2883, 2915, 2957, 3058. H NMR spec-
3
trum, δ, ppm: 1.22 d (3H, 5-Me, J = 6.18 Hz), 1.25 t
(3H, CH2CH3, 3J = 7.1 Hz), 2.51 d.d.d (1H, 4-HA, 2J =
3
(3H, 5′-Me), 1.29 d (3H, 5-Me, J = 6.1 Hz), 2.21 m
3
3
2
3
18.0, J4,5 = 3.5, J3,5 = 1.9 Hz), 2.60 s (3H, MeC=C),
(2H, 4′-H), 2.59 d.d.d (1H, 4-HA, J = 18.1, J = 3.5,
2
3
3
2
3.13 d.d.d (1H, 4-HB, J = 18.0, J4,5 = 10.7, J3,5
=
1.7 Hz), 2.67 s (2H, 6′-H), 3.22 d.d.d (1H, 4-HB, J =
1.6 Hz), 4.10 q.d (OCHA, 2J = 2.1, 3J = 7.1 Hz), 4.23 m
18.1, J = 10.1, 3J = 1.4 Hz), 4.28 m (1H, 5-H), 5.17 s
3
3
13
(1H, 5-H), 4.76 s (1H, C=CH), 6.68 t (3-H, J =
(1H, C=CH), 6.91 unresolved triplet (3-H). C NMR
1.6 Hz). 13C NMR spectrum, δC, ppm: 14.55 (CH3CH2),
15.64 (5-Me), 18.54 (MeC=C), 42.04 (C4), 52.02 (C5),
58.51 (OCH2), 85.81 (C=CH), 143.17 (C3), 155.64
(MeC=C), 168.77 (C=O). Found, %: C 61.38; H 8.57;
N 14.38. C10H16N2O2. Calculated, %: C 61.20; H 8.22;
N 14.27.
spectrum, δC, ppm: 18.21 (5-Me), 28.01 (5′-Me), 28.26
(5′-Me), 32.00 (C5′), 39.71 (C4), 41.58 (C4′), 49.64
(C6′), 51.65 (C5), 96.79 (C2′), 144.45 (C3), 157.15 (C3′),
196.06 (C=O). Found, %: C 69.64; H 8.45; N 13.26.
C12H18N2O. Calculated, %: C 69.87; H 8.79; N 13.58.
5,5-Dimethyl-3-(3,5,5-trimethyl-4,5-dihydro-1H-
pyrazol-1-yl)cyclohex-2-en-1-one (IVj). Yield 97%,
viscous oily substance. IR spectrum, ν, cm–1: 413, 460,
500, 533, 593, 687, 741, 793, 820, 833, 860, 880, 900,
925, 953, 990, 1013, 1033, 1107, 1137, 1144, 1240,
Ethyl 3-(3,5,5-trimethyl-4,5-dihydro-1H-pyrazol-
1-yl)but-2-enoate (IVg). Yield 99%, mp 96°C. IR
spectrum, ν, cm–1: 628, 725, 798, 842, 888, 907, 958,
983, 1000, 1040, 1095, 1125, 1100, 1247, 1317, 1358,
1377, 1422, 1558, 1640, 1670, 2915, 2933, 2980.
1
1271, 1367, 1420, 1543, 1613, 2867, 2953. H NMR
3
1H NMR spectrum, δ, ppm: 1.25 t (3H, CH3CH2, J =
spectrum, δ, ppm: 1.08 s (6H, 5′-Me), 1.55 s (6H,
5-Me), 2.00 s (3H, 3-Me), 2.13 s (2H, 4′-H), 2.61 s
(2H, 4-H), 2.81 s (2H, 6′-H), 5.37 s (1H, 2′-H).
13C NMR spectrum, δC, ppm: 16.74 (3-Me), 26.61
7.1 Hz), 1.56 s (6H, 5-Me), 1.98 s (3H, 3-Me), 2.54 s
3
(3H, MeC=C), 2.75 s (2H, 4-H), 4.06 q (OCH2, J =
13
7.1 Hz), 4.92 s (C=CH). C NMR spectrum, δC, ppm:
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 12 2007